A variety of parallel optical communications modules exist for simultaneously transmitting and/or receiving multiple optical data signals over multiple respective optical data channels. Parallel optical transmitters have multiple optical transmit channels for transmitting multiple respective optical data signals simultaneously over multiple respective optical waveguides (e.g., optical fibers). Parallel optical receivers have multiple optical receive channels for receiving multiple respective optical data signals simultaneously over multiple respective optical waveguides. Parallel optical transceivers have multiple optical transmit and receive channels for transmitting and receiving multiple respective optical transmit and receive data signals simultaneously over multiple respective transmit and receive optical waveguides.
For each of these different types of parallel optical communications modules, a variety of designs and configurations exist. A typical layout for a parallel optical communications module includes a circuit board, such as a printed circuit board (PCB), a ball grid array (BGA), or the like, on which various electrical components and optoelectronic components (i.e., laser diodes and/or photodiodes) are mounted. In the case of a parallel optical transmitter, laser diodes and one or more laser diode driver integrated circuits (ICs) are mounted on the circuit board. The circuit board has electrical conductors running through it (i.e., electrical traces and vias) and electrical contact pads on it. The electrical contact pads of the laser diode driver IC(s) are electrically connected to the electrical conductors of the circuit board. One or more other electrical components, such as a controller IC, for example, are typically also mounted on and electrically connected to the circuit board.
Similar configurations are used for parallel optical receivers, except that the circuit board of the parallel optical receiver has a plurality of photodiodes instead of laser diodes mounted on it and a receiver IC instead of a laser diode driver IC mounted on it. Parallel optical transceivers typically have laser diodes, photodiodes, one or more laser diode driver ICs, and a receiver IC mounted on it, although one or more of these devices may be integrated into the same IC to reduce part count and to provide other benefits.
The circuit board typically has one or more heat sink devices mounted on the upper surface thereof. The heat sink devices are typically made of materials of good thermal conductivity (e.g., metal), and are attached to heat generating components with thermal pads. The heat sink devices can have various shapes. The electrical and optoelectronic components are typically attached by a thermally conductive material to these heat sink devices to enable heat generated by them to pass into and be dissipated by the heat sink devices. A heat sink device is also typically attached to the top of the module. Heat sink devices all have the same general purpose of receiving heat generated by the respective components and absorbing and/or spreading out the heat to move it away from the components. Heat generated by the components can detrimentally affect the performance of the parallel optical communications module.
There is an ever-increasing need to increase the number of channels of parallel optical communications modules and the speed at which they operate. In order to meet these needs, heat dissipation devices need to be practical in terms of space utilization and highly effective at dissipating heat. As the number of channels increases, the number of components that generate heat also increases. At the same time, implementing adequate heat dissipation solutions becomes even more difficult due to the higher density of components in a smaller area.
Accordingly, a need exists for methods and systems that provide improvements in heat dissipation and that are efficient in terms of space utilization.